the older brother, tamerlan, was in russia last year for six months. we have no idea why he was there. they're suspicious about what he w -- why he was there. did he get training, guidance, financing for a terror attack? investigators do, and the national security intelligence establishme menment in the unit states is go back and see if they missed any signs. we have been told again and again there was no so-called chatter. they didn't hear anybody talking about a potential attack. they didn't think an attack was imminent or possible at the boston marathon that day. they'll go back and see what m. they do detective work in reverse. they'll see what the plans were for the future of those two. they're going to search the computers, scrub them. see if the brothers were radical ized in some way, through the internet or overseas connections. >> what is the scarier scenario? to think that these young men were lone wolves who were radicalized by the viral islamist online philosophy? or is it scarier to think their connected to a terror group? >> i thing they'